Billionaire investor and founder of Greenlight Capital, David Einhorn, again went all 'activist' on Apple Inc. (NASDAQ:AAPL) earlier today. He is still pushing for the company to use some of its massive cash, totaling upwards of $137 billion.

His latest idea includes using the cash to offer preferred stock to shareholders. He prefers this, and things it will better reward shareholders, as opposed to buybacks or dividends.

Einhorn says the preferred says will...

Unlock about $150 per share in additional value for shareholders, compared with a maximum of about $85 per share through buybacks or dividends.

In his presentation and call today, Einhorn also called out Dell, saying he sold the stock due to the same issue, hoarding too much cash.

An interesting out take from Einhorn's talk today was that he he compared cash hoarding to having an inventory problem; where technology companies let cash sit idle on their balance sheets for years, earning near nothing.

Einhorn has taken the proposal a step further by filing a lawsuit to counter a proposal by Apple that will prevent Apple's board from issuing preferred shares. Despite the case being heard in court earlier this week, there has been no resolve. The proposal will be put to a vote at Apple Inc. (NASDAQ:AAPL)'s annual meeting next week.